Sources tell ‘Extra’ that Britney Spears and fiance Kevin Federline were driving at about 50 miles per hour in Los Angeles when they blew a tire in her new Range Rover. Luckily, Spears was okay, and so was the blinding 5-carat ring on her finger. A shaken Britney was comforted by Federline while a mechanic worked to get them back on the road.